What if he IS a she and SHE is pregnant!!?
I know I know. . . but let me dream for a second, k?
Cuz' then there'd be, like, zillions of tiny little Sparklings running around everywhere. . .d'aaaaaw! And we could ALL have one, and keep it, and love it, and name it Spark. . . something. And they'd be soooo cute and we'd squeeze them, but they'd zap us, so we wouldn't, cuz' they're fishes. . .
But... okay, I'm about to betray (again) the fact that I know nothing about fish. But. . . catfish lay eggs, right? Do they get chubbier when they're, like, getting ready or anything - full of roe - regardless of a male being present? My frog does. Frogs and catfish are JUST the same, neh? Just. Exactly. The same. . . *pokes Sparky's tum* I wish he had a bellybutton. He'd be THAT much cuter. . .
Oh! And congrats on the roomie - does he/she/it (this is the tank where you put creatures of dubious gender) have a name yet?